The present invention relates generally to sensor systems, and in particular to a system and method for providing static reference outputs for sensor systems.
Sensor systems implemented on aircraft, for example, may provide information utilized by various aircraft systems. One such sensor system, for example, is an angle of attack (AOA) sensor having a rotatable vane that is utilized to determine the aircraft angle of attack (i.e., an angle between oncoming airflow or relative wind and a reference line of the aircraft, such as a chord of a wing of the aircraft). The AOA sensor is mounted to the aircraft such that the rotatable vane is exposed to oncoming airflow about the aircraft exterior. Aerodynamic forces acting on the rotatable vane cause the vane to align with the direction of the oncoming airflow (i.e., along a chord extending from a leading edge to a trailing edge of the vane). A resolver circuit may be utilized to provide an analog electrical output that is indicative of the position of the rotatable vane. A controller is then able to determine the AOA based on the resolver output.
These sensor systems may be utilized in flight critical applications, for example, such as stick-shaker applications. In a stick-shaker application, the control yoke of the aircraft is configured to vibrate rapidly to alert a pilot of a possible stall condition. The sensed AOA being greater than a threshold value may be an important factor utilized in stick-shaker applications. Traditionally, to test the stick-shaker application, the mechanical parts of the AOA sensor were moved to a position indicative of an AOA that is greater than the threshold value. This requires costly extra circuitry/mechanical parts. It is desirable to provide reference outputs for AOA sensors, as well as any other sensors that may include resolver circuits, without the need for complex circuitry and moving parts.